Shot blasting is a common technique to change surface characteristics of a variety of different parts. A shot blasting wheel can propel shot or small spheres of hard material to impact and smooth a rough surface, roughen a smooth surface, shape a surface, or remove surface contaminants. Shot blasting can be achieved by a wheel and blade assembly accelerating shot to a relatively high velocity towards the material surface of an object or group of objects to be treated. It is typical to configure equipment such that shot material is introduced into the center of a rotating wheel having a plurality of radially disposed blades mounted thereon. The shot is accelerated by the blades attached to the spinning wheel, and can be directed toward an opening in a control cage where the shot may exit to contact the objects being treated. Wheel blasting is often referred to as airless blasting, as no fluid propellant is used.
Because of the abrasive quality of the shot and the high speed at which the wheels and blades are turned, blades wear out and require frequent replacement. Removable blades have been developed to allow a user to replace blades individually. A variety of designs of blade and wheel combinations have been utilized in an attempt to efficiently direct shot within a shot blasting machine.